1. Section 2.4

2. Representing Data Standard I&E: 1a Mastering Concepts: 50(69-71) Terms: 43
Homework:
Cornell Notes: 2.4
Section Assessment: 45(45-48)
Mastering Problems: 50 (86-87)
6 stamps

3. Section 2-4 Create graphics to reveal patterns in data.
Section 2.4 Representing Data
Create graphics to reveal patterns in data.
independent variable: the variable that is changed during an experiment
Interpret graphs.
graph
Graphs visually depict data, making it easier to see patterns and trends.

4. Mastering Concepts: 50(69-71)
69. Which type of graph would you choose to depict data on how many households heat with gas, oil, or electricity? Explain. (2.4)
A bar graph could be used with the method of heating on the x-axis and the number of households on the y-axis.
If the data include all the households for a region, relative numbers could be converted to a percentage and expressed as a circle graph.

5. Mastering Concepts: 50(69-71)
70. Which type of graph would you choose to depict changes in gasoline consumption over a period of ten years? Explain. (2.4)
line or bar graph because they can show how consumption varies with time
71. How can you find the slope of a line graph? (2.4)
Choose two points on the line. Divide the difference in the y values by the difference in the x values.

6. 45. Explain why graphing can be an important tool for analyzing data.
Section 2.4 Assessment page 45
45. Explain why graphing can be an important tool for analyzing data.
It provides visual information about relationships between variables, relative amounts, or parts of a whole.
46. What type of data can be displayed on a circle graph? On a bar graph?
parts of a whole; how a quantity varies with a factor

7. Section 2.4 Assessment page 45
47. If a linear graph has a negative slope, what can you say about the dependent variable?
It decreases in value as the independent variable increases.
48. When can the slope of a graph represent density?
when mass is the y value and volume is the x value

8. Problem-solving Lab Stopping distance (m) Speed (m/s) 18 11 32 16 4920 68 25 92 29

9. How does speed affect stopping distance?
100 80 60 40 20
Speed
(m/s)
Distance (m)

10. Section 2-4
Graphing
A graph is a visual display of data that makes trends easier to see than in a table.

11. Section 2-4 Graphing (cont.)
A circle graph, or pie chart, has wedges that visually represent percentages of a fixed whole.

12. Section 2-4 Graphing (cont.)
Bar graphs are often used to show how a quantity varies across categories.

13. Section 2-4
Graphing (cont.)
On line graphs, independent variables are plotted on the x-axis and dependent variables are plotted on the y-axis.

14. Section 2-4
Graphing (cont.)
If a line through the points is straight, the relationship is linear and can be analyzed further by examining the slope.

15. Section 2-4
Interpreting Graphs
Interpolation is reading and estimating values falling between points on the graph.
Extrapolation is estimating values outside the points by extending the line.

16. Section 2-4
Interpreting Graphs (cont.)
This graph shows important ozone measurements and helps the viewer visualize a trend from two different time periods.

17. End of Section 2-4